Automotive trim parts and protective molding are often prepared via injection molding techniques with the manufacture of elongated moldings being greatly aided by gas assisted injection molding techniques. For some applications, it is desirable to form deep drawn molded parts wherein the transverse cross section of the elongated part approximates the letter “C”.
For example, it is desirable to provide deep drawn side sill and rocker panel moldings wherein the exterior, show surface of the part (i.e., the outer part surface between the opposed generally horizontal ends of the “C”) has an increased height dimension measured transverse to the longitudinal axis of the part so that the part will extend closely to the road surface exhibiting minimum ground clearance. This effect is not only popular from an aesthetic perspective, but the low disposition of the part also helps to serve an air damming effect helping to promote aerodynamic stability of the vehicle during driving.
Molding of deep drawn substantially “C” cross sectioned plastic parts is difficult. If the opposing longitudinally disposed edges converge toward each other, it is difficult to remove the part from the mold in the absence of elaborate sliding mechanisms.